Pris: 29,-

Abstrakt

Computational Fluid Dynamics (CFD) is quickly becoming a widely used analysis tool in the design of occupied spaces. The accuracy of the simulation depends largely on the accuracy of the method used to model the diffuser. This study builds upon the work previously published by the authors. Two box method type boundary conditions with either a total pressure definition or a constant velocity are used to model a common square plaque diffuser. These boundary conditions are thoroughly evaluated by studying the behavior of the jet created by the diffuser that is placed close to a wall. Comparisons are made to experimental data as well as to CFD results that use a full geometric model of the diffuser. In general, the development of the jet is under predicted by the CFD results and the temperature profiles are not predicted as accurately as the velocity profiles. The accuracy of the box method tends to degrade as the diffuser is moved closer to the wall and as the flow rate is increased. The results also show no clear advantage in using a total pressure over a constant velocity since the predictions of both are nearly identical.

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